Salt and acid-containing mixtures can effectively be separated by processes based on polymeric ion-exchange membranes, especially diffusion dialysis. The transport of selected inorganic acids (HCl, HF, HNO3, and H2SO4) through an anion-exchange membrane Fumasep-FAD was experimentally studied in a two-compartment batch dialyzer. The process was quantified by permeability of the membrane obtained from the dependences of the acid concentrations and liquid volumes upon time in both compartments of the dialyzer. The experiments revealed that this membrane is highly permeable for the acids investigated.